Heretofore various forms of end cap enclosures have been available to cover the ends of fluorescent lamps and their lampholders to make bare lamp fluorescent luminaires more esthetically acceptable.
U.S. Pat. No. 2,345,982 is a patent directed to a structure known to the present inventor of such prior art and which is directed to a device designed to cover the end of a fluorescent lamp and its lampholder.
This prior art device has been found to be unsatisfactory and inadequate in two respects. One is this prior art device depends upon a tension clamping action and when it is applied to a fluorescent lamp it can scratch the glass bulb and result in a dangerous bulb implosion. The other is that the device covers a significant section of the luminous part of the bulb and results in a loss of useful light.
The present invention overcomes these deficiencies of the prior art as the end cap does not touch the glass part of the bulb. It, also, covers only the non-luminous base of the lamp so that all of the lamp's light output is available for useful lighting purposes.
Further, as will be hereinafter more readily apparent, the lockable feature of the present invention deters the theft of lamps especially where a bare lamp fixture is used at an easily reached location as on the walls of an apartment or hotel corridor.
The benefit of this present invention lies in its potential for making bare lamp fluorescent luminaires more esthetically acceptable as replacements for incandescent luminaires. It is well known that fluorescent lighting only takes one-half to one-fourth the electricity required by comparable incandescent lighting.
This present invention, while applicable to a broad field of applications is best illustrated as to its value toward energy conservation as in the lighting of apartment interior corridors where incandescent lighting is currently the principal form of light. Typically sixty watt long-life incandescent lamps are used consuming approximately 525 kilowatt-hours per year as they are on continuously for 8760 hours. A bare 15 watt fluorescent fixture which consumes 20 watts with its ballast only uses about 175 kilowatt-hours and gives about the same amount of light. Thus if such a sixty watt incandescent fixture can be replaced with a 15 watt fluorescent fixture the savings in energy would amount to 350 kilowatt-hours per year for each fixture replaced. The basic reason such replacements have not been widely done is that bare lamp fluorescent luminaires of acceptable pleasing appearance have not been available. The fluorescent lamp's cylindrical shape is basically pleasing but the appearance of the lamp base and the lampholder is not as esthetically acceptable. The end cap of this invention by covering the lamp base and the lampholder with a pleasing appearing structure makes the use of bare lamp fluorescent fixtures more acceptable especially where they can be viewed at close range and thus permit the energy conservation benefits of fluorescent lighting to be more widely used.